The invention relates to a device for vertical and angular position adjustment of vehicle seats, and more particularly it relates to an adjustment device of the type in which a seat carrier and a bottom frame fixed to the floor of the vehicle are linked by adjustable members to form together a five-bar linkage, the adjustable members including at least one support or link between one end portion of the seat carrier and the bottom frame and at least one elbow joint between the other end portion of the seat carrier and the bottom frame; the lower lever of the elbow joint and the support lever are provided respectively with a gear segment which is in mesh with locking pawls controlled by means of a pivotably supported hand lever.
A vehicle seat adjuster of the above type is known, for example from the German published application No. 2,206,884. The gear segment on the adjustment members linking the base frame are internal gear segments cooperating respectively with arresting gears. The counteracting arresting gear assigned to the supporting arm is made in the form of an externally geared sliding member arranged on a radially shiftable cam supported on the first bearing element; the contacting arresting gear assigned to the elbow lever joint is provided also with external gears and is made in the form of a rocking lever controlled by a cam arranged on a second bearing element. Both cams are linked to connecting rods which are connected to each other by means of a tension spring and have at their free ends slots for engagement with a lever that is pivotably supported in the base frame and carries a control grip.
These conventional vertical and angular position adjusting devices for vehicle seats are assembled of a relatively large number of component parts so that production and assembly costs are relatively high and in addition such complicated structures have the disadvantage that they are prone to rattle and are susceptible to failures.